How to enable PX4FLOW control to update the local position for Pixhawk!

I am new to pixhawk. I am using pixhawk 2.4.8 and PX4 firmware version 1.5.5. Please let me know, how could i enable PX4FLOW to update the pixhawk local x and y positions. is it just to connect the PX4FLOW (say by I2C) and the lcoal position of the pixhawk starts updating ? Or Do i need to do some settings for enabling the PX4FLOW for this purpose ?

I already did the calibration of the PX4FLOW and also the GPS is disabled.